By Elizabeth Armstrong

The Recording Industry Association of America has just filed 532 lawsuits against music file swappers who share an average of at least 800 songs with other online music fans, reports The Associated Press. It is the largest single sweep of lawsuits the group has made since it launched its campaign against file sharing last summer.

Currently, the RIAA knows the Internet protocal addresses of the 532 targeted file sharers, but not their names or addresses. It plans to discover the identity of each defendant through Internet service providers such as Verizon Internet Services Inc. Verizon successfully challenged the industry's use of copyright subpoenas in December. The US Court of Appeals for the District of Columbia ruled that the recording industry cannot use subpoenas to force Internet providers to identify music downloaders without filing a lawsuit.

Hence today's filing of hundreds of lawsuits. How Internet providers respond remains to be seen, though Verizon has been fighting to maintain the privacy of its customers since the RIAA's campaign to stop file sharing began.

The move comes on the heels of a report released by The NPD Group, a marketing research firm, which found that the number of people downloading music illegally increased in October and November after a six-month decline.

NPD's MusicWatch Digital service, which monitors household usage of peer to peer services, reports that the number of households downloading digital music files was up 14 percent in November 2003 compared with September, and that the number of people who report using P2P services rose from 11 million to 12 million in that same period.

"It's important to keep in mind that file sharing is occurring less frequently than before the RIAA began its legal efforts to stem the tide of P2P file sharing," Vice President Russ Crupnick said. "We're just seeing the first increase in these numbers. NPD will continue to monitor whether it's a temporary seasonal blip, or a trend that suggests that the industry should be more aggressive in capping the use of illegal methods to acquire digital music."

The RIAA announced Wednesday morning that after the identity of each defendant is determined, the group will attempt to negotiate a financial settlement with each person before updating the lawsuit with the defendant's name and transferring the case to the proper courthouse.